The present invention relates to a watch demanding a high pressure waterproofing like a diver's watch for instance.
In the diver's watch, in order that a crown is not moved carelessly when carried, a structure for locking the crown (this structure is referred to as screw lock in this specification) is adopted utilizing a mesh of screw.
Conventional screw lock structures are shown in FIG. 6 or FIG. 7. In both of these drawings, a sign 1 denotes a case band, a sign 2 a winding stem pipe, and a sign 3 a crown. A waterproof gasket 4 is interposed between a crown cylinder portion 3a, of the crown 3, inserted into the winding stem pipe 2 from an outside of the case band 1 and the winding stem pipe 2. In FIG. 6 or FIG. 7, a sign 5 denotes a winding stem protruding from a main body portion of timepiece movement not shown in the drawing, a sign 6 a spring washer attached to the winding stem 5, and a sign 7 a coil spring accommodated in the crown cylinder portion 3a and biasing the winding stem 5 through the spring washer 6.
In the conventional example of FIG. 6, the winding stem pipe 2 inserted from an outside of a winging stem attaching hole 1a of the case band 1 is fixed using a metal brazing filler material 8, whereby a waterproofing between the case band 1 and the winding stem pipe 2 is ensured by the brazing material 8. A female screw portion 3c formed in a crown main portion 3b of the crown 3 is detachably meshed with a male screw portion 2a formed in an end portion outer circumference, of the winding stem pipe 2, protruding outside the case band 1.
In the conventional example of FIG. 7, a male screw portion 2b formed in an intermediate portion outer circumference of the winding stem 2 is meshed with a female screw portion 1b of the winding stem attaching hole 1a of the case band 1, the winding stem pipe 2 is attached to the case band 1, and a waterproof gasket 9 compressed by screwing the winding stem pipe 2 is interposed between the case band 1 and the winding stem pipe 2. The female screw portion 3c formed in the crown main portion 3b of the crown 3 is detachably meshed with the male screw portion 2a formed in the end portion outer circumference, of the winding stem pipe 2, protruding outside the case band 1.
In either constitution of the conventional examples, at an ordinary time, the crown 3 can be locked by screwing the crown main portion 3b into the male screw portion 2a and, when operating the timepiece movement, the winding stem 5 can be rotation-operated by drawing out the crown 3 after the screwing of the crown 3 with respect to the male screw portion 2a has been released.
Further, in the conventional watch, after an elastic member has been inserted into a center hole of the crown, there is inserted a crown core in which an elastic ring having a slanting face at an outside of its one end has been mounted in a circumferential groove. At this time, although an outer shape of the elastic ring mounted in the crown core is made larger than a deformed inner diameter portion of the crown, it is inserted by a slanting face formed in a collar portion, the slanting face of the elastic ring, and an elastic deformation of the elastic ring. Further, the crown core inserted into the center hole of the crown becomes impossible to be drawn out of the crown by the elastic ring because there is no slanting face inside an inner end of the collar portion and there is also no slanting face outside the other end of the elastic ring (for example, Patent Document 1, JP-UM-A-7-26792 Gazette (pages 4-5, FIG. 1)).
Further, in the conventional watch, a pipe in which a screw portion has been formed in an inner wall of its inner end portion is watertightly fixed firmly to a through-hole concerning an inside by an outer wall of the case band. In an axle portion of the crown, there are respectively formed a sliding hole through which the winding stem slides, a screw portion where the screw portion of the pipe is meshed with an outer wall of a tip portion, and a groove portion for mounting a waterproof gasket to the outer wall in an approximately center portion. The winding stem is attached so as to slide in the sliding hole of the crown and engage with a tip of the sliding hole. The crown in which the gasket has been mounted in the groove portion is inserted into the pipe. Next, if the inserted crown is rotation-operated under a state of being pressed in an internal direction of the case band, the screw portion formed in the axle portion is meshed with the screw portion of the pipe, so that the crown is locked (for example, Patent Document 2, JP-UM-A-4-79293 Gazette (pages 3-5, FIGS. 1-2)).
As to the watch having the screw lock structure, by the fact that the crown 3 is repeatedly rotation-operated and the like, the female screw portion 3c of the crown 3 and the male screw portion 2a of the winding stem pipe 2 are worn or abraded, so that there is a case where a function of the screw lock is decreased.
In the conventional example of FIG. 6, since the case band 1 and the winding stem pipe 2 are brazed and thus the waterproofing between them is ensured, a part exchange around the crown 3, which accompanies a detachment of the winding stem pipe 2 from the case band 1, is impossible. Thereby, in case where the screw lock function is decreased, an exchange of a timepiece armor assembly including the case band 1 is obliged, so that its improvement is demanded.
In the conventional example of FIG. 7, since the winding stem pipe 2 is screwed into the case band 1, in principle the part exchange around the crown 3 including the winding stem pipe 2 is possible. However, in the constitution of this conventional example, a torque is applied to the winding stem pipe 2 every time the crown 3 is meshed with the winding stem pipe 2 or this meshing is released. Accompanying this, the screwing of the winding stem pipe 2 into the case band 1 is loosened, so that there is a possibility that the waterproofness by the waterproof gasket 9 is decreased. As a countermeasure against this, there are many cases where an adhesive is filled in a screw portion between the winding stem pipe 2 and the case band 1. Accordingly, in the conventional example of FIG. 7, since a detachment of the winding stem pipe 2 from the case band 1 is very difficult, actually the part exchange around the crown 3 is impossible. Thereby, in case where the screw lock function is decreased, the exchange of the timepiece armor assembly including the case band 1 is obliged, so that its improvement is demanded.
A problem to be solved by the present invention is to provide a watch in which, in case where the screw lock function has decreased, the part exchange around the crown is made possible while ensuring the waterproofness.